#include<stdio.h>
int in_a=1, in_b=2, out_sum;
int main() {
    asm("pusha;         \
    movl in_a, %eax;    \
    movl in_b, %ebx;    \
    addl %ebx, %eax;    \
    movl %eax, out_sum; \
    popa                \
    ");
    printf("sum is %d\n", out_sum);

    return 0;
}